A variety of electrosurgical devices are available for performing different surgical procedures. For example, coagulation procedures require an instrument that is capable of coagulating tissue to stop or minimize the flow of blood at the surgical site. Such instruments may also be capable of flushing an irrigation solution into the area where the surgeon is working to remove bits of tissue or blood. In other alternatives, these instruments may be capable of aspirating fluids from the site. Such fluids include liquids, such as saline solution or blood, and gases, such as smoke or air.
For example, electrosurgical forceps have a pair of blades that are used to grasp and coagulate tissue. The forceps may be monopolar or bipolar. In monopolar forceps, one or both of the blades form an electrode in electrical communication with an electrical generator. Current flows from the active electrode through the patient's tissue to a dispersive electrode in contact with the patient's skin, which may be at some distance from the forceps, and back to the generator. In bipolar forceps, each blade of the pair comprises an electrode in communication with the electrical generator.
In some forceps, an irrigation channel is formed along one or both of the blades to allow an irrigation fluid, such as saline solution, to flow through the channel and out the outlet near the tip of the blades to flush bits of tissue or blood away from the area where the surgeon is working. See, for example, U.S. Pat. No. 6,228,084.
In another known type of bipolar coagulating instrument, a pair of electrodes is arranged coaxially. A suction channel is provided along the central axis to draw fluids away from the surgical site. See, for example, U.S. Pat. Nos. 5,989,249 and 6,406,476.
In instruments that provide both coagulation capabilities and irrigation or aspiration capabilities, the instrument must be connected to both an electrical generator via an electrically conducting cord and to a fluid pump or vacuum compressor for irrigation or aspiration via a lumen. The electrically conducting cord is formed with a pair of copper wires each coaxially surrounded by an outer insulation. The fluid tubing for the lumen is typically formed from a suitable plastic material. It is known to form an electrically conducting cord and a lumen into a cable assembly by bonding the cord and lumen together with a glue or other bonding solution.